Gov. Arnold Schwarzenegger vetoed a bill Monday that would have prohibited smoking at nearly all state beaches and parks, saying the law would have been too intrusive and would not have done much to curb litter on California's shoreline.

The groundbreaking legislation would have created the nation's most far-reaching smoking ban in a state that already restricts people from lighting up in cars with children, restaurants and bars. State Sen. Jenny Oropeza, D-Long Beach, who authored the bill, said Schwarzenegger's veto stands in "stark contrast to what is already being done at more than 100 local cities and counties statewide," including smoking bans at beaches and parks controlled by local jurisdictions. Oropeza and other supporters said the bill was necessary to cut down on litter, secondhand smoke and forest fires at the 278 parks and 64 beaches owned by the state.

"I'm sorry the governor did not agree with this widely supported effort to increase public awareness about the environmental threats carelessly tossed cigarettes are doing to our marine life and to the great outdoors," Oropeza said in a written statement.

But Schwarzenegger - whose cigar habit is well known - wrote in his one-page veto message that Senate Bill 4 was an "improper intrusion of government into people's lives." Noting that he has supported other smoking bans, the governor nonetheless said that Oropeza's bill "crosses an important threshold between state power and command and local decision making.

"There is something inherently uncomfortable about the idea of the state encroaching in such a broad manner on the people of California," Schwarzenegger wrote. "With respect to marine debris, I understand the challenge cigarette butts cause to our beaches and marine life. But, this bill applies the ban solely to those beaches and parks owned and operated by the state of California ... As we have seen, marine debris and litter know no boundaries."

Schwarzenegger also noted that the state Department of Parks and Recreation has some discretion to ban smoking in parks and beaches under certain circumstances, such as when fire hazards exist.

The bill, which was first introduced as a broader measure in 2006, would have imposed a $100 fine on people who violated the ban. After changes made during the legislative process last year, it exempted all state-owned campsites and parking lots as well as a vehicle recreation area in San Luis Obispo County, and could only have been enforced in areas where signs were posted advertising the ban.